Study On Insect Resistance Of Cotton Defense-related Genes By Using VIGS Technique

Cotton(Gossypium arboretum)is a significant source of cash crops,textile fibers,feedstuffs and oil and biofuel products.However,Helicoverpa armigera(Hübner)is becoming more and more serious,affecting its yield.Our group previously cloned insect may be associated with a polyphenol oxidase gene GhPPO1 and leucine-rich protein kinase GhLRR1 gene from cotton.In order to study the insect resistance of this gene,the gene silencing recombinant vector pTRV2-GhPPO1,pTRV2-GhLRR1 was constructed by virus-induced gene silencing(VIGS),and the methods of molecular biology and experimental zoology were used this study is of great significance to understand the interaction between cotton and cotton bollworm and to clarify the molecular mechanism of cotton insect resistance.The specific research contents are as follows:(1)Construction of silencing vector by VIGS technique,successfully constructed pTRV-GhPPO1,pTRV2-GhLRR1vector,effectively silenced GhPPO1 and pTRV2-GhLRR1,which reduced the contents of endogenous GhPPO1 and GhLRR1.Were 20%and 45%lower than the blank control group(CK),respectively,29%and 54%of the empty vector control group(pTRV0).(2)The quality of cotton bollworm was measured by silencing GhPPO1 and GhLRR1 cotton for 72 hours.The results showed that the survival rate of Helicoverpa armigera(P<0.05),and 2.91(P<0.05)times in blank control group,which was significantly higher than that of control group(P<0.05).The survival rate of Helicoverpa armigera was significantly lower than that of cotton bollworm(Helicoverpa armigera)35%(P<0.05)in the blank control group and 56%in the empty vector control group(P<0.05).(3)It was clear that the expression of GhPPO1 gene in direct feeding site and indirect feeding site was obtained after feeding the 2~stt instar cotton bollworm.The expression of GhPPO1 in the leaves of GhPPO1 plants was higher than that of the indirect feeding leaves after 18 h and 72 h treatment.The trend of the changes in the control group(CK)and empty vector control group(pTRV0)And the difference was significant.The results showed that the GhPPO1 gene had a response to mechanical injury.The expression of GhLRR1 was significantly higher than that of GhLRR1,and the expression of GhLRR1 was significantly higher than that of GhLRR1.The GhLRR1 gene had a significant response to the feeding injury of cotton bollworm(4)The expression of GhPPO1 and GhPPO1 cotton in different parts of cotton was investigated by qRT-PCR.The gene content of leaves in GhPPO1 cotton plants was the lowest,and the silencing effect was the best.A silent GhLRR1cotton plant,the leaves of the old leaves the lowest gene content,the best silence effect.